Wine derived additives as poly(butylene succinate) (PBS) natural stabilizers for different degradative environments

A grape pomace extract (GPext) and a grape seed extract (T) have been melt mixed within poly(butylene succinate) (PBS) and tested as natural stabilizers. Their effect on the PBS stabilization has been evaluated trough thermo-mechanical degradative tests (reprocessing), thermo-oxidation (oven aging), thermogravimetric analysis (TGA) and biodegradation tests. GPext and T have been deeply analyzed in terms of polyphenolic profile and bioactivity to connect the stabilization's results with the antioxidant's structures. Additive T exhibited the best results, maintaining unaltered the PBS molecular weight both after six reprocessing steps and after 300 h of oven aging and to increase the degradation temperature of more than 20 °C. These encouraging results have been explained by the long-chains polyphenols present within T (medium degree of polymerization of 10.8), by the excellent radical scavenger activity of T (6.0 mM TEAC) and by the low releases of peroxides from T (0.06 µM H2O2).